ECG Basic Electrocardiogram 3

Question 1

On standard ECG paper, how many seconds does one small (1 mm) box represent horizontally?

Accepted Answer

0.04 seconds

Answer

At the standard 25 mm/sec speed, each small horizontal box equals 0.04 seconds.

Question 2

Which limb electrode is considered the ground (neutral) and produces no tracing?

Accepted Answer

Right leg (RL)

Answer

The right leg electrode serves as the ground/reference and does not generate a lead tracing.

Question 3

Which chest lead is placed at the fourth intercostal space to the right of the sternum?

Accepted Answer

V1

Answer

V1 is positioned at the fourth intercostal space just right of the sternal border.

Question 4

A wandering baseline artifact on an ECG is most often caused by:

Accepted Answer

Patient movement or loose electrodes

Answer

Baseline wander typically results from patient motion, respiration, or poorly attached electrodes.

Question 5

60-cycle (AC) interference on an ECG appears as:

Accepted Answer

A thick, fuzzy fine oscillation on the baseline

Answer

AC interference produces uniform fine, fuzzy oscillations from nearby electrical sources.

ECG (Electrocardiogram) Practice Test